Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A power management integrated circuit comprising: a boost converter configured to supply a first voltage to a power amplifier, the power amplifier configured to support a first maximum voltage; a charge-pump circuit configured to supply a second voltage to a power amplifier controller of the power amplifier, the power amplifier controller configured to support a second maximum voltage, the second maximum voltage less than the first maximum voltage; and an overvoltage protection circuit that, when a power surge event occurs, configures the charge-pump circuit with a surge-protection configuration preventing the second voltage from exceeding the second maximum voltage, the overvoltage protection circuit including a comparator configured to compare a first bandgap reference voltage and an input voltage supplied to the power management integrated circuit to determine an occurrence of the power surge event, and the comparator further configured to compare a second bandgap voltage reference and the input voltage when the occurrence of the power surge event is detected to determine when the power surge event has ceased.
2. The power management integrated circuit of claim 1 wherein the second bandgap reference voltage is less than the first bandgap reference voltage.
3. The power management integrated circuit of claim 1 wherein the charge-pump circuit includes a plurality of transistors in communication with an output pin of the charge-pump circuit.
4. The power management integrated circuit of claim 3 wherein the overvoltage protection circuit configures the charge-pump circuit with the surge protection configuration by disconnecting at least one of the plurality of transistors in communication with the output pin of the charge-pump circuit when the power surge event occurs.
5. The power management integrated circuit of claim 4 wherein the overvoltage protection circuit configures the charge-pump circuit with a non-surge protection configuration when the power surge event ceases by reconnecting the at least one of the plurality of transistors in communication with the output pin of the charge-pump circuit.
6. The power management integrated circuit of claim 3 wherein a first transistor of the plurality of transistors connects an input voltage supplied to the power management integrated circuit to an output pin and a second transistor of the plurality of transistors connects the output pin to an external capacitor.
7. The power management integrated circuit of claim 1 wherein the charge-pump circuit includes a phase transistor between an input voltage pin of the charge-pump circuit and an external capacitor that is external to the charge-pump circuit.
8. The power management integrated circuit of claim 7 wherein the overvoltage protection circuit configures the charge-pump circuit with the surge protection configuration by disabling the phase transistor when the power surge event occurs.
9. A wireless device comprising: a power amplifier module including a power amplifier configured to support a first maximum voltage and a power amplifier controller configured to bias the power amplifier and to support a second maximum voltage that is less than the first maximum voltage; and a power management integrated circuit including a boost converter, a charge-pump circuit, and an overvoltage protection circuit, the boost converter configured to supply a first voltage to the power amplifier, the charge-pump circuit configured to supply a second voltage to the power amplifier controller, and the overvoltage protection circuit configured to prevent the second voltage from exceeding the second maximum voltage during a power surge event by configuring the charge-pump circuit with a surge-protection configuration when the power surge event occurs, the overvoltage protection circuit configured to determine the occurrence of the power surge event by comparing a first bandgap reference voltage to an input voltage supplied to the power management integrated circuit, and the overvoltage protection circuit further configured to determine that the occurrence of the power surge event has ceased by comparing a second bandgap reference voltage to the input voltage.
10. The wireless device of claim 9 wherein the second bandgap voltage is less than the first bandgap voltage.
11. The wireless device of claim 9 wherein the overvoltage protection circuit prevents the second voltage from exceeding the second maximum voltage by at least disconnecting at least one transistor in communication with an output pin of the charge-pump circuit when the power surge event occurs.
12. The wireless device of claim 9 wherein the overvoltage protection circuit prevents the second voltage from exceeding the second maximum voltage by at least disabling a phase transistor when the power surge event occurs.
13. A method of performing surge protection of a wireless device, the method comprising: determining, by a power management integrated circuit, an operating mode of the wireless device, the power management integrated circuit including a boost converter configured to supply a first voltage to a power amplifier of a power amplifier module; determining a first overvoltage protection threshold of a charge-pump circuit based at least in part on the operating mode of the wireless device, the charge-pump circuit configured to supply a second voltage to a power amplifier controller of the power amplifier module; determining a first input voltage supplied to the power management integrated circuit of the wireless device at a first time period; determining that the first input voltage exceeds the first overvoltage protection threshold; configuring the charge-pump circuit with a surge-protection configuration responsive to determining that the first input voltage exceeds the first overvoltage protection threshold; determining a second overvoltage protection threshold of a charge-pump circuit based at least in part on the operating mode of the wireless device; determining a second input voltage supplied to the power management integrated circuit of the wireless device at a second time period that is later than the first time period; determining that the second input voltage does not exceed the second overvoltage protection threshold; and configuring the charge-pump circuit with a non-surge-protection configuration responsive to determining that the second input voltage does not exceed the second overvoltage protection threshold.
14. The method of claim 13 wherein the first overvoltage protection threshold is lower than a maximum voltage supplied by the boost converter to the power amplifier when a power surge event is not occurring.
15. The method of claim 13 wherein configuring the charge-pump circuit with the surge-protection configuration includes disconnecting at least one of a plurality of transistors in communication with an output pin of the charge-pump circuit.
16. The method of claim 13 wherein the second overvoltage protection threshold is lower than the first overvoltage protection threshold.
17. The method of claim 13 wherein configuring the charge-pump circuit with the non-surge-protection configuration includes connecting at least one of a plurality of transistors in communication with an output pin of the charge-pump circuit, the at least one of the plurality of transistors previously disconnected responsive to the determination that the first input voltage exceeded the first overvoltage protection threshold.
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July 24, 2018
December 1, 2020
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